SO One of the way I think a world can get really tied together is through descriptions you give to your players. Expressions, common knowledge, etc. can help you as a GM create immersion on your players as well as setting the tone to your world. The way your players interact with your characters/setting depends a lot on how you describe it to them as well as enriching the cultural experience of the game.
That said, on to collective nouns:
I also HAD to use this image
A collective noun is not only a useful tool do describe a bunch of something in a more eloquent manner it also reveals the cultural lens in which that something is seen. For instance, describing a group of owls as a Parliament not only tells what you assume, culturally of owls, but also of parliaments. So I'll go over a couple of nouns used to describe certain types of creatures and what that may mean in my current campaign world:
Ghouls (Court of) Cursed by hunger, but not by a lack of mind, ghouls have, or at least try to maintain, some sort of composure and humanity. This ended up with ghouls giving themselves or maintaining titles they held while human, usually tinted by their form of gallows humor, so it's not uncommon t have ghouls calling themselves Baron, Countess, Queens, etc. but different from human nobility titles ghouls tend to "rule" over more abstract concepts related to their current situation i.e.: The Countess of vermin, The Baron of kidneys, Duchess of offal. And courts don't necessarily mean that ghouls live in huge agglomerations or keeps, a ghoul "castle" and court could describe the 5 ghouls that are currently haunting the ruined manor nearby town. But don't take them as as savages, because even though their clothes and decoration are decayed and destroyed they will still entertain you as nobles would a visitor, especially if they have eaten recently.
Giants (Clan) while mostly solitary giants have social structures and hierarchies. Their bonds, however, are not formed exclusively by familial connections. Giant societies are formed by oaths, which can be inherited down generations. These structures also bleed out to giants relations with other beings. At least that's what most scholars agree to the reason of why giants tend to protect seemingly worthless or abandoned constructions.
Trolls (Family) Different from giants trolls usually spend most of their lives inside their birth family, being fiercely loyal to their siblings and parents. Of course incest is rampant on most troll families which also tend to make trolls very distinct from region to region.
Zombies (Wave, Horde, Storm) Given their brainlessness and relentlessness the mindless dead are seen mostly as a natural occurrence. Waves are described to crash, or pass over a village/town/city/country.
Golems (Company) Golems are beings born out of pragmatism, automation and function, they exist for a work and they act as such. If they could speak they'd describe themselves as such as well.
Kobolds (with a dragon: Brood, Without a dragon: Nuisance) Without a being to worship and bathe on the magical radiation kobold are little more than leathery hairless evil dogs. Tying knots on horse's manes, destroying kitchens, basically being a nuisance. Now, when they find something bigger than themselves they change, they get smarter, start planning and stop being a nuisance, start calling themselves after their living deity and get as proud as the dragons that they serve.
Harpies (Parliament) A Scholar once wrote: "After the kings went back to their thrones a purge of what they called 'peasant works' happened and new bestiaries were commissioned to the universities that were still standing, usually the author was of noble birth, or the writing was supervised by a noble. I shouldn't surprise anyone that they decided to use the government type most common in the large free cities to describe a group of screeching carrion feeders."
Puddings (Bloat) Nobody can be sure, but most thinkers believe that all puddings are part of the same pudding that broke off into smaller chunks. So when you get two puddings together they form a bigger pudding (their color doesn't affect this). After getting large enough a bloat will start making it's way around the world, eating everything in sight and finding other bloats, sometime smaller pudding break off along the way and the cycle continues.
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I guess this will be the last post of the year! Have a Great passage and I hope you are enjoying whatever it is that I am doing here ! :)